Machine and method of shaping silica and the like



June m, 1933,

z. F. HOOPER ET AL MACHINE AND METHOD OF SHAPING SILICA AND THE LIKE '7Sheets-Sheet 1 Filed June 24, 1931 Inventors, Irvin F H00 per Berbhold FNledergesass hlllp K Devers. by Then" Attorney June 13, 1933. g! FHQQPER r AL 1,914,2(15' MACHINE AND METHOD-0F SHAPING SILICA AND THELIKE Filed June 24, 1931 7 Sheets-Sheet 2 Inventors: Irvin FHoopef,Berthold FT Niecterrgesass' Philip K. Devers. y Their Attorney.

June 13, 1933. a. F. HOOPER ET AL MACHINE AND METHOD OF SHAPING SILICAAND THE LIKE Filed June 24, 1931 7 Sheets-Sheet 3 ////I/I/I/////// u I"Wham Inventors: Irvin F Hooper, Benthold F Nledengesass.

l l'nhp K. Dsvens. by Then" Attorney June 113, 1933. n. F. HOOPER ET ALMACHINE AND METHOD OF SHAPING SILiCA AND ,THE LIKE Filed June 24, 1931 7Sheets-Sheet 4 6 l na Inventors. Irvin E Hocvper, Bert 910M F Niedrcesass, Phiip K. Haw-swa :3 y I T5165 Att-cmngy.

June 13, 1933. I. F. HOOPER ET AL 1,914,205

MACHINE AND METHOD OF SHAPING SILICA AND THE LIKE Filed June 24. 193i '7Sheets-Sheet 5 y r%& e s er n r Cl 6 P t r t H E D t n ,A m m r Imm m av H .h r

o 1% Y r b e. B

June 13, 1933. 1. F. H OOPER ET AL 1,914,205

MACHINE AND METHOD OF SHAPING SILICA AND THE LIKE Filed June 24, 1931 7Sheets-Sheet 6 f F ig.l

Inventors: Irvin T. Hooper;

Berthold F. Nieder-e sass.

Philip K. Devers,

Their Attorney.

June 13, 1933. PER T AL 1,914,205

MACHINE AND METHOD OF SHAPING SILICA AND ,THE LIKE Inventors:

Irvin FHoopsr, I I Berthold T. Niederesass,

Phili K. Dever s,

Patented June 13,-

UNITED STAT S- PATENT OFFICE TO' GENERAL ELECTRIC OOH- -IMiACH-IN1'2-METHOD OF SHAPING $ILIOA. AND THE LIKE n Application filed June 24,

The present invention includes both a I method and anapparatus forfabricating shaped articles from elongated stock, such, for example,as'tubing. Our invention is particularly applicable to the manufactureof articles, from a refractory vitreous material, such as fused silica,which, because of its physical properties, cannot be readily shaped" bymethods commonly in use for making shaped articles from other materials,as for example, pressing, casting, ma-

chinirig or sintering. Our invention can be advantageously 'appliedtothe manufacture of spark plug insulators.

While the-novel process which constitutes one aspect of our inventionmay beemployed for the hand fabricatlon of shaped articles, it may beeven more advantageously carried out by an automatic machlne as hereindescribed and claimed. The advantages of such a machine in the quantityproduction of standardized articlesaccompanied by uniformity and lowcost are obvious.

Among the novel features of our invention are the following: A method offabr eating articles involving the combination of endwise andtransversely applied moldin pressures upon a portion of elongated stocmaterial having a longitudinal channel therethrough' and which stock hasbeen rendered plastic by heating. Also afabricating' operation'involving the combination of fusing and twisting operations on elongatedstock having a longitudinal channel therethrough whereby an internalbore of substantially uniformcross-section is sized in the fused portionof the stock and in approximately symmetrical relation with respect tothe enlargement.

Our invention involves also the combination of externalshapingoperations upon material rendered plastic by heat combined '1931. SerialNo. 546,588.

portion of the stock to produce a firing tip. Our invention utilizes inthe fabrication of silica articles a heating operation whereby only anouter layer or skin of material is rendered plastic, the article as awhole remaining non-plastic, and in this condition bein indented orgrooved for producing a condltion of discontinuity which will rendereasy severance of a completed article from unformed stock material atsuch grooved region. Our invention involves the combination of shapingand cutting operations whereby an insulator body may be formed from theelongated stock provided with an enlargement comprising. suitable bearinsurfaces for the insulator and with atapered portion comprising a firingtip which is shaped to the desired configuration, and the tip thusformed trimmed at its end to produce the desired tip length.

i The machine constituting a feature of our invention provides aplurality of mechanism groups herein termed stations for carrying outthe various stages of fabrication of shaped articles of exactpredetermined contour from tubing, or other elongated stock material ofsimple-form, including means for carrying out the above process stepstogether with such auxiliary steps as may be required for producingcompleted articles.

The'stock is advanced from station to station, the mechanism of eachstation performing one or more operations'on the stock, such operationsbriefly comprising an" upsetting operation whereby a sphericalenlargement in a part of the stock is produced. The ma-( chine providesmechanism for carrying out external shaping operations which may becombined with internal shaping operations whereby, a desired contour isglven the article; also means for carrying .out an indenting operationpreparatory to a severing operation whereby finally the completedarticle is broken away from the unfinished stock and is delivered by themachine.

These and other features of our invention will be described in greaterparticularity in the following specification taken in connection withthe accompanying drawings.

IRVIN F; HOOPER, OF-SAUGUS, AND BERTHOLD F. NIEDERGFSASS AND PHILIP I.

' DEVERS, 0F LYNN, MASSACHUSETTS, ASSIGNOBS '25., A CORPORATION OF IIEWYORK tion; Fig. 4 represents a section of the ing station on line Hof Fig.1; 1g. 5

represents a section through the holding chuck on the line b-b of Fig.3; Fig. 6 represents a side elevation and partial section of the firstoperating station or upsetting station and illustrating the rocker armfor up and down motion; also the relative motiont of the stock andupsetting abut-' ment; Fig. 7 represents a plan of operating arm (Fig,6) and partial section of relate parts; Fig. 8 represents the sizingpin; Fig.

9 represents a modification in elevation and partial section of theconstruction shown in gig. 6, dispensing with the use of apin;

1 tia? shaping station; Fig. 11 represents a side elevation of Fig. 10showing flames and abutment for bringing the forming rolls intooperative position; Fig. 12 is a sectlon 7 taken on line d-d of Fig. 11and showing bearing and pin and operating sleeve in section; of Fig. 11;Fig. 14 represents a front elevation of the final taper molding station;Fig. 15 represents a side elevation of Fig. ld'showing flames; Fig. 16represents a side elevation in partial section of the indenting stationpreliminary to severing; Fig. 17 rep resents a lan of cam operatingparts of Fig: 16; Fig. 18 represents a side elevation of the severing orbreahng-ofi' station showing hammer; ig. 19 represents a front elevationof Fig. 18; Fig. 20 represents a plan view of the anvil-wheel atbreaking-ofi' station; Fig. 21 represents a detail of the gaugingspindle shown in Fig. 3; Fig. 22 represents adetail of the upsetting orenlarging operation; Fig. 23 represents a detail of the prelirnlnary orrough rolling or molding operation; Fig. 24represents a detail of thefinal molding operation; Fig. 25 represents a detail of the roughtapering operation; Fig. 26 represents a detail of the final taporingoperation; Fig. 27 represents an enshap larged section of Fig. 26,illustrating ing 'tip end and cutting ofi of tip ig. 28

represents adetail of the indenting station;

Fig. 29 represents a-detail of'the'severing or breaklng-ofi station;Fig. 30 re resents a modification of the arrangement s own in -Fig. 10for hringing' shaping or molding means into operative position, and Fig.31 represents a perspective view oi'f thee'ssential operating mechanismsof the machine and more clearly illustrating their cooperativerelationships.

aug- 10 represents a front elevation and par- I section of the rolling,or enlargement ig. 13 is a section taken on line We have hereinafterdescribed an auto-- aaiaaoa ment of our invention and comprises details7 of importance in that particular embodiment, the invention may becarried out by other forms of mechanism suitably applied as covered inthe appended claims.

The general operation and application of the salient parts will first'bedescribed by us, after which the construction and operation of thevarious mechanisms and certain modifications thereof will be describedin detail, and the manner in which they are brought into cooperativeaction.

While in the description which follows reference is made specifically totubes or tubing, it is to be understood that our invention is notlimited to the employment of tubular stock. In the specific productionof spark-plug insulators, We prefer to use tub- 'ing. The machine isadapted to receive and operate upon suitable lengths of the silicatubing which is to be worked upon for shaping into the requiredconfiguration and subsequently detached and delivered automatically to asuitable receptacle provide to receive the finished insulators. 5

Referring to Figs. 1 and 31 of the drawings, A, B, C, D, E, F, G and Hrepresent a plurality of stations whereat the various steps of operationof the invention are performed. Referring more specifically to Figs. 1,2, 3, 4 and'5, each length of tubing 9 to be operated upon is fedlengthwise through the spider guides 10 provided with chucks 11 adaptedto hold it and grip it tightly or to open and permit feeding, asdesired. The spider uides 10 are carried on a spider 12 mounte on apedestal 13 (Fig. 2) onthe table of the machine frame 14:. The tube 9 isheated at a suitable region of its length while suspended in the chucks11, and while thus held, 'endwise pressure so as to enlarge the diameterof the heated region is applied to the heated stock at its free end(Fig. 6) by means of an upwardly moving part 15.

A. number of tubes may be heated, worked,

figures, extending through a sleeve 16 in the pedestal 13 is a shaft 17'mounted in suitable bearings and connected at its top end to a largegear 18 rotated by said shaft, this gear 18 meshing with smaller gears19, (Fig.

31) one on each spindle for turni the respective chucks 11 to rotate thetubing held thereby. The driving mechanism for the a gear 29 mounted onthe countershaft 28,

another countershaft is driven, upon which are mounted gears 31 and 32and a bevel gear 33 which meshes with a gear 34 fixed onthe lower end ofshaft 17; The shaft 17 is thus driven in the direction of the arrow androtates the gear 18 at the top of the shaft in the same direction andrevolves the chucks 11 and the stock held therein. The cam actuatingmeans provided for operating the various levers and fingers at thevrespective stations will now be described, toether with the means forrotating the boreorming pin.

Shaft 35 (Fig. 31) is driven by means of gear 36 through idler gear 37having meshing engagement with said gear 36 and with gear 32 oncountershaft 30, the shaft 35 being rotated inlthe direction of thearrow shown on gear 36. By means of cams 38' and 38 fixedly mounted onshaft 35 in conjunction with rollers 39 and 40 and fingers 41 and 42,the operating motions at the gauging station (station A) are controlled.The operating motions of station B '(upsetting or enlarging station) areaccomplished by means of cam 43 fixedly secured also to shaft 35engaging with roller 44 on lever 45 this lever in turn being connectedto a shaft 46 by means of link 47 and crank lever 48 fixed on shaft 46.A finger 49 on shaft 46 effects the upsetting motion at station B.Rotation of the bore-forming pin is secured at this station by means ofthe chain 50 (driven in the direction of the arrow) on the sprockets 51and 52, the latter being fixed on a vertical shaft 53. At the lower endof this-shaft is a bevel gear 54 meshing with a similar gear 55 fixedlycarried on the end of countershaft 28.

The mechanism for performing the required operating motions at stationsC, D,

E and F will now be described. On shaft 35 is fixedly secured cam 56which actuates the,

forked members or fingers 57. The shaft 46 actuates finger 58 foroperation at stater being connected by a link 63 and crank 64 toshaft'60. Y

The operating motions at stations E and F (the tapering stations) arecontrolled by means of cams 65 and 66 (on shaft 35) which actuatefingers 67 and 68 by means of rollers 69 and 70 res 'ectively on saidfingers. Stations G and (the indenting and cutting-01f stationsrespectively) are operated by fingers 71 and 72 mounted on shaft 73which is connnected by crank 74 and link 75 with crank 64.

The means for supplying the gas (oxygen and hydrogen) to the variousburners will now be described. The tanks 76 and 77 contain. oxygen andhydrogen, the two gases being in the separate tanks, the pipes 78 and 79conveying the gas through saidpipes to the gas valves 80 and 81. Bymeans of suitable connections, such as by rubber gases'to the gas valves86 and 87 and from the outlet pipes 88 and 89 to a gas manifold (notshown) from which it is distributed to the burners at stations C, D, E,F and G. Of course, the specific arrangements for supplying'the fuel forheating may be modified in any suitable manner.

On one end of shaft 35 is a cam 90 engaging with a roller 91 operativelyarranged on a lever 92 and connected by a link 93 with an arm 94 on thegas valve 80 and 81. The cam 90 is so timed that the fires at station Bwill play uponthe work at this station by means of suitable burners atthe predetermined required sequence of operations at this station. Thearm 94 operates to actuate short levers 95 and 96 on the gas valves 80and 81, thus regulating the flames at station B from pilot condition tofull flame condition.

The gas valves 86 and 87 are similarly operated by means of. shortlevers 97 and 98, :trm99, link 100 and crank 101, the latter beingsuitably mounted on shaft 60. By

virtue of this arrangement, the flames or may beimparted to the variouschucks and stock supported therein. This indexing mechanism and mannerof operation is best illustrated in detail in Fig. 31 wherein cam.step-by-step or station-to-station movement 103 on shaft 35 actuateslever 104, thus in 3 turn operating bell-crank 105, rod 106, crank 107and reciprocating rod 108 (all suitably supported) to release indexingplate 109, permitting the latter to drop and allow clutch 110 to closedand engageably coop- "crate with the fixed gear'111 on shaft 17.

Indexing plate 112 is secured rigidly to sleeve 16 and is integrallyconnected with plate 113. A cam 114 rotates'with indexing plate 109, theformer carrying indexing pin 115. In the plate 112 are slots 116 withwhich pin 115 engages to turn sleeve 16 and integrally connected parts.The earn 114' is so shaped as to cause revolution of sleeve 16 andabove-mentioned parts, thus rotating chine from motor speed.

Referring to Fig. 3, the gauging or adjustable stop 118 is normally inthe position shown being supported on a. spindle 119. The spindle 119 isenclosed by a sleeve 120 having a bearing 121 and the gauging stop118rests on a flange or table 122 provided with a sleeve 123 and securedto the spindle 119 at the threaded top of the latterand adjusted to apredetermined height by means of a set screw 124. Cooperating with thechuck 11 at this station is a chuck arm 125 mounted on pivots 126, thechuck arm engaging a cam roller 127 mounted ona. cam-operated shaft 128supported in a bearing 129. The cam-operated shaft 128 is operated bymeans of a cam 38 on" shaft 35 (Fig. 31). -The chuck 11 is normally openwhen stock 9 is inserted therein. The dropping ot the cam-operated shaft128 by means of cam 38 locks the chuck on the stock. Cam shaft 119 nowdrops, by means. of cam. 38, a suficient distance to clear the end ofthe stock 9 and permit the latter to he responsive tosubsequentoperations.

The mechanism by which the upsetting or enlarging operations areperformed are illustrated in 6 wherein the sleeve 130 is slotted toreceive the end of the forked finger 49 whereby the latter may beconnected to the rolls 131, the arm 49 beingactuated to slide in theslot 132 to reciprocate the upsetting head 15. A pin 133 (preferablysquare as shown in Fig. 8) is secured in the head 15, so that when thelinger 49 is actuated to cause upward movement of the upsetting memberand pin, a bore of the. size as determined by the size of the pin willbe formed in the channel of the stock. On the downward motion of saidarm, the pin'is withdrawn. j I The upsetting head 15 is given a relativemotion with respect to the chuck 11 and stock 9 by means of the chain50, as previously described, and may be driven in the speed of themaopposite direction to the chuck 11 and stock 9. The upsetting head 15is provided with a heat-resisting sleeve 1340f material such as or slipof the latter with reference to the speed of rotation of chuck 11 andstock 9. A. similar pin is provided at each succeeding station at whichthe article or insulator may be rotated and a predetermined diameter ofbore is to be sized in the channel.

Referring to Figs. 10 and 11 (the enlargement or ball-rollin station),cam 56 on shaft 35 causes the torked finger 57 to rise and actuate rod135 to also rise and carry with it the cam head 136 comprising thespring 137 upon which is seated a supporting plate 138 for the shapingrolls 139. These rolls 139 may be either of metal or of a highlrefractory material, such as zirconia. he plate 138 is provided withlugs 140 having projections u on which the rolls are'mounted, and bingelevers 141 to which are attached springs 142 seated in lugs 143. Camrollers 144 travel on the cam-head 136 downwardly when said head rises,thus closing-in theshaping rolls 139, and when the rod 135 drops, therollers 144 travel upwardly on the cam-head by the expansion of thespring 137. The function of the springs 142 is to provide a downwardbias of the shaping rolls 139 onthe stock 9. Suitable flames 145emerging from burners 146 are provided at the required working stationsto heat the stock to the required temperature. In Figs. 10 and 11reference may be mad to the means which adjust the limiting height towhich the ball-shaping and tapering rolls respectively may rise. A stop147 on a rod 148 is adjustable as to its height with relation to thebase fixture 149 of the machine. The stop 147 is adjusted so that itsbottom surface will engage with the plate 138 at 150 (Figs. 11 and 15)and when this engagement occurs, the spring 137 will compress andclose-in the ball rolls or tapering rolls, as the case may be, toshape'the stock under pressure by the mechanism dc scribed heretofore.

In Figs. 14 and 15, the same general mechanism and movements areinvolved for this station- (the tapering station) as for the enlargementor ball-rolling station. The rolls 151, however, have a trustro-conicalshape, as shown, but as illustrated in Fig. 15, the main body' of therolls may be heated by flames 145, while the top portion 152 thereof isrelatively cold or unheated. The purpose of this procedure is to providerelatively cold or rigid seating surfaces for the enlargement, while thelower or heated portions of the rolls are giving a tapered shape to thearticle or insulator under formation, and insuring a symmetricalshapefor the tapered tip of the insulator. The steps of forming the desiredcontour of the enlargement (the latter being identified by the numeralmay be accomplished at either the same station, or additional shapingstashown in Fig. 31) and 158 represents a mechanism by the fixture.

short spindle or stud shaft supported bx bearings 159 carried by thefixture 156.

set-screw 160 on finger 71 is provided for adjusting the angularrelation or travel of the wheel 163 with respect to the stock when thewheel leaves the latter. A second adjusting screw 160 on stud shaft 158ad justs the tension of the spring (shown in dotted lines) on said shaftfor the'purpose of maintaining the wheel 163 in the desired pressurerelation with the stock. Supported by the spindle 154 is a head 161(adjustable as to height by means of the screw-thread spindle 154) inwhich is mounted a stud 162 upon which is rotatably carried a groovingwheel 163 free to rotate and which'engages with the stock 9 above theenlargement 153. When finger 71 is caused to throw in the spindle 154and sleeve 155, the

grooving wheel 163 indents the heated skin of the stock 9 and the wheel163 rotates by virtue of its frictional engagement with the rotatingstock 9. After the groove is made, the cam-actuated shaft 73 and finger71 operate to permit the'grooving wheel 163 to drop out-of engagementwith the stock.

Figs. 18, 19 and illustrate the detailed of the breaking-off stationwherein 164 represents the base of the fixture 165 bolted to the frame14. A shaft or spindle 166 in a sleeve 167 is attached to a lever 72fastened to the shaft- 73 (Fig. 31) and is caused to rise thereby untilthe hammer 168 is in operative relation with the stock 9 (see also Fig.29). The fixture also supports a wheel 169, the support for the samebeing mounted in a bearing 170 carried \Vhon the chuck 11 is indexed toarrive at this station, the wheel 169 rotates in the groove which hasbeen formed at the indenting station and the hammer 168 .taps the stock9 in the relation best shown-inFig. 29, breakingit off with quite aclean or regular fracture, and the finished article or insulator rollsdown a chute 185 (Fig. 18) into a suitable receptacle (not shown).

In Fig. 9,- a modification is shown of the means for sizing the requiredbore diameter through the insulator when the stock is in the form of atube, having a channel 171 and an .airor gas connection 172communicating with the channel 171. Air or other gas under pressure ispumped through the passage of the connection 172,v and while the tube islocally heated to plasticityfthe air pressure is so regulated orproportioned as to prevent collapse of the plastic inner walls of thetube, or if they are allowed to collapse, to control the same tomaintain a bore of the desired uniform. cross-section in the tubechannel.

Referring to Fig. 30, a modification shown of the means for controllingthe engagement of the shaping rolls with the stock. In this case, levers173 which support the rolls are designed to come in towards the stock ina lateral or horizontal line instead of on-an angle, as in the otherfigures involving this general type of mechanism.

It has been found desirable to water cool certain parts of the machine,(especially in proximity to the quartz stock hol ing means) due to thehigher temperature of operation in working quartz, as. distinguishedfrom the working of glass. Water cooling of such a machine forfabricating articles of glass would, in fact, be doubtless impracticablebecause of the danger of cracking the glass articles subjected to thevarious operations of the machine.

To this end a suitable water receptacle or trou h 174 (Fig. 4) abovespider 12 is pro-,"

vide the wall of which surrounds the spider 12 and gear 18. A'sump 175also surrounds pedestal 13. An inlet drip pipe 17 6 is suitable arrangedabove the trough 174 for conveying water to said trough, and an overflowoutlet 177 from tropgh .174 is provided in boss 178, a drain pipe 179being fitted into said outlet at the bottom thereof and the other end ofthis drain pipe terminates in sump 175, supplying water to thelatter,pipe 179 revolving with spider 12. A drampipe 180 carries the water into be cooled and used over again, as desired.

12o sump 175 away either as refuse water or In proximity to chucks 11 isan annular 181 and 182, having each an inlet and outlet connection (notshown). This waterjacket structure may extend circumferentially aroundthe machine under all the chucks 11 at the various stations, or only atsuch stations where water-cooling is v-water-jacketed structurecomprised of ducts needed. The structure is supported by means ofsuitable standards 183, 18 1 fastened to any accessible location on thema-- chine frame 14.

l The operation of our invention is as folows:

3) of the machine is set at the required height to space thepredetermined length of stock 9, the stock resting on the stop as it isfed through the openjaws of the chuck 11. The jaws are then closed bythe operation of the machine wherein cam-operated'shaft 128 and roller127 engaging with chuck-arm 125 lock the chuck 11 on the stock 9, andthe stop 118 drops about by the operation of the machine at the righttime period in the cycle of operations. This "leaves the stock suspendedwith a free end above the stop 118. The next step is to produce anendwise pressure upon this free end, and as themachlne is properlyindexed by the indexing mechanism hereinbefore described,.the'chuck 11with its stock 9, is carried around ci'rcumferentially to the upsettingor enlarging station (Fig. 6) where the flames 145 heat it locally tofusion temperature. At this statlon, the member 15 is raised, causing itto impinge against the free end of the stock andu set it, producing theenlargement 153 t ereof. Simultaneously, the pin 133 carried in member15 enters the channel in the tubular stock and sizes said channel tothe-required diameter and produces the required bore, the member 15 andpin 133 being given a relative motion with respect to t e direction ofrotation of the stock 9, either by means of gearing or by the chain orby the sllppage or lag of the part 15 with reference to the rotation ofthe stock. The machine is again indexed, and the chuck 11 and stock 9with its enlargement as now formed is carried to what we designate asthe ball-' rolling, station. (Figs. 10, 11, 23 and-2t),

tional station or. stations provided for final rolling to' the ultimateshape and dimensions, or these rolling operations may all be performedin one operation at this station, as found the most desirable. Beforeeach rollingoperation, the rolls and the pin are smeared with alubricant, such as graphite,

The abutment or gauging stop 118 (Fig,

antenna which may mixed with a vapori zablmmaterial. When applied to thepinthe lubricant becomes vaporized and serves to. produce pressure inthe bore and prevent collapse of the walls around the pin. After theball-rolling operations are performed, the pin 133 is again withdrawn,and the work thus far accomplished is indexed to carry it to thetapering station, it being understood that the flames 1 15 are broughtinto and out of operation locally upon the stock as desired.

We have illustrated in Figs. 14, 15, 25 and 26 two tapering stations,but it is to be understood that the tapering may also be performed inone operation, if desired. Fig.

25 represents the character of rolls utilized for the rough taperingstation, and Figs. 14, 15. and 26 that employed in the final taper-, ingstation. In the case of the final tapering station, the rolls are heatedat the portions 151 thereof by the impingement thereon of the flames,145, Fig. 15, and the portions 152 thereof are unheated, thus providingrigid or relatively cold bearing surfaces for the convex portions of theenlargement 153, and thus giving a definite taper to the tip of theinsulator, as determined by the adjacent configurations of the rollportions 151. These rolls are made of suitable material, such asgraphite, or metal, but preferably the latter. The tapering rolls at thefinal tapering station are provided at thebase of each roll with acutting wheel 151,.and having a contour as shown in the enlargedsectional view, Fig. 27. It will be seen that by virtue ofthe diameterand shape of these wheels that when they are brought into contact withthe insulator tip they cut ofl the end of said insulator to trim the tipas in Fig. 27, the cutting wheels being rotatable .by frictionalengagement with the rolls as in the case of the indenting station. Incase the length of the tapered portion is the final length desired, thecutting-ofl operation of the ta ered portion may be dispensed with, andt e shaping of the tip only may be performed at this stage of theoperations. At the taperingstations, a pin smaller in diameter than thepin 48 employed at the previous stations is used so that the bore in thetip will be smaller than the bore through the enlargement arid shaft,although in line with and communicating with the larger bore. This is toreduce the possibility of plugging up of the tip bore with residue fromthe products of combustion of the engine where the insulator is used forspark plugs to be utilized in internal combustion engines.

After'the taper has been given to the insulator and the tip thereofshaped and cut elf as described, the cam 66 on the shaft 35 causes thetapering rolls to drop out of operative engagement with stock 9. The

machine is again indexed to rotate the article thus far formed andsuspended in the head 11 until said article arrives at the indenting orgrooving station, Figs; 16 and 28. Here the grooving wheel 163 isbrought into proper relation with the stock 9, which is locally heatedin such a manner that slightly more than the skin or outer surface ofthe stock is penetrated by the wheel, and

a weak plane formed-inthe stock at a region sufliciently remote from theenlargementf153 to-constitute a shaft for the article or msulator. Thisheating of the skin only of the insulator prevents distortion of thebore or enlargement, as the plastic temperature is not reached in theinterior of the insulator. It would be diflieult if not impossibletocarry out such an operation with glass or other'vitreous material.

The grooving wheel 163'is' now dropped away from the stock by the properactuationof finger 71 on shaft 73, the machine is again indexedautomatically .as before, and the next or breaking-off station isreached, Figs. 18, 19,

20 and 29. At this" station, the anvil or wheel 169 has a similar shapededge to that of the grooving wheel 163 at the indenting station, sothatwhen the anvil is brought up to the stock, the edge will enter thegroove in the skin of the latter, which groove was formed at theindenting station, The hammer 168 is brought into play by the operationof finger 72 and caused to lightly tap the tapered portion of. thearticle or insulator resulting in 'a regular fracture at the groove,.asbest illustrated in the diagrammatic view (Fig.v 29), and dischargingthe insulator through the chute 185 into a suitable receptacle toreceive the same.

All of the above operations are performed automatically in sequence, thechucks 11 being loaded with the raw stock at the loading or spacingstation, and the finished product being broken off and discharged at thebreaking-oil station.

What we claim as new;and desire to secureby Letters Patent of-the'UnitedStates, 1s j 1. The method of forming shaped articles from elongatedstock of vitreous material which consists in heating a zone of saidstock to atemperature ofplasticity, exerting endwise pressure on saidstock to ,,,pro-' duce an enlargement at said heated zone,

molding said enlargement externally to produce a desiredconfigurationthereon, forming a channel of predetermined cross-section ,throughsaidenlargement and through portions ofsaid stock adjoining saidenlargement and severing said enlargement together with adjoiningextensions from the main body of said stock.

2. The method of forming shaped. articles from elongated stock ofvitreous material having a channel therethrough which consists inrotating said material, applying upon a zone of said material a flamewhich is capable of' heating said material to a temperature ofplasticity, exerting sufiicient endwise pressure upon said stock toproduce an enlargement of diameter at said heated zone, molding saidenlargement externally -to substantially spherical configuration,

molding a portion of said stock adjacent .said enlargement, sizing abore in said stock uniform cross-section through a desired length of thechannel, producing an indentation in said stock at a region removed fromsaid enlargement, and severing said material at said indentation.

4. The method of forming shaped articles .such as electrical in'sulatorsfrom-elongated stock having a channel extending longitudinallytherethrough which consists in heating a zone of said stock to atemperature of plasticity, exerting sufiicient endwise pressure on saidstock to produce an enlargement atthe heated zone, externally moldingsaid enlargement to desired configuration, SlZlIlg a bore ofsubstantially uniform cross-section through a desired length of saidstock, shaping a tapered tip on said stock adjacent one side of theenlargement, trimming the end of the tip to provide a predetermined tiplength, and severing the stock on the opposite side of the enlargementso as to include as parts of the detached insulator the enlargement, ashaft adjacent one side thereof and an insulator ti on the opposite sidethereof with a bore o desired cross-section extending through theinsulator.

5. The steps in the process 9f forming shaped articles of vitreoussilica tubing, wherein the stock is heated to fusion at a desired zoneand endwise pressure appliedto form an enlargement at said zone, whichconsists in molding the enlargement andadjacent portions to desiredshape and to provide a shaft and a tapered tip on opposite sides of theenlargement respectively and rotating 'said tubing concentrically arounda pin of predetermined diameter to form a bore of substantially uniformcrossseetion in the finished article extending lengthwise therethrough.

6. The steps in the processof forming shaped articles of vitreous tubinghaving a channel extending lengthwise therethrough wherein the stock isheated to fusion temperature at a desired zone and endwise pressureapplied to form an enlar ement at said zone, consisting of rotating saidtubing concentrically about a pin of predetermined diameter to form abore of substantially uniform cross-section in the finished article,said pin being coated with a lubricant to prevent adherence of the pinwith the inner walls of the tubing during rotation of the latter.

7. The method of forming spark plug insulators from elongated stock ofvitreous silica having a channel extending lengthwise therethrough whichconsists in rotating said stock on its longitudinal axis, si-

multaneously heating a zone of said stock A adjacent 'one end thereof toa temperature of plasticity, exerting endwise pressure on said stock toproduce an enlargement at said heated zone, shaping said enlargementexternally to form a substantially spherical configuration thereon,sizing a bore of substantially uniform cross-section through saidenlargement and through portions of said stock adjoining saidenlargement, shaping a portion of the stock on one side of theenlargement to provide a tip for said insulator, and severing theinsulator thus formed from the stock on the side of the largement whilstpreventin collapse of the bore wall, tapering the stoc at one portionthereof adjacent the enlargement, and severing the stock at theuntapered portion to provide a shaft for the insulator.

9. The method. of forming spark plug in: sulators from elongatedvltreous material having a channel extending lengthwise therethroughwhich consists in heating a zone of said stock adjacent one end thereofto a temperature of plasticity, exerting endfwise pressure on said stockto produce an enlargement at said heated zone, sizing the channel in theheated portion of the stock to provide a bore for the insulator, shapingthe enlargement externally to form c'onvex bearing surfaces thereon,shaping a portion of the stock adjacent the enlargement to form atapered tip, trimming the tip end to tubing to a temperature ofplasticity whilst forming a bore of the required diameter in the heatedportion of the channel, forming an enlargement between the ends of thetubing, tapering the tubing below the enlargement, cuttin ofi thetapered endat a predetermined istance below the enlargement, skinheating the tubing at a predetermined distance -above the enlargement,grooving the tubing at this skin heated portion, and breaking off thetubing mechanically at the groove. 1

11. The method ofinaking spark-plug in- I I sulators consisting inheating to p astic ternperature a portion of silica stock having achannel therethrough, upsetting the stock by application of pressure onone endthereof to form an enlargement, producing relative rotary motionat the ends of the heated portion of the stock whereby uniformity ofchannel cross-section and symmetrical relation of the channel withrespect to the enlargement and adjacent portions is secured, sizing thechannel through said enlargement and adjacent portions to form a definitelbore therefor, shaping the portions adjacent the enlargement, andsevering the article thus formed from the stock.

12. The combination of a holding means through which apredetermined'length of elongated stock maybe fed longitudinally,

means for heating a portion of the stock fed through the holding means,mechanism arranged to produce a bore of substantially uniformcross-section in the heated portion of the channel, means for applyingan endwise pressure on one end of thestock in the direction of theopposite end to enlarge the diameter of the stock at the heatedportion,- 'means for sha ing the a enlargement thus formed, means ortapering thestock below the enlargement and means for severing the vstock between the holding means and the endwise pressure-producing meansso'as to include the enlargement and the tapered part in the portionsevered from the predetermined' length of elongated stock with theaforesaid bore therethrough.

13. A machine comprlsing a holding means for suspending a predeterminedlength of elongated'stock with one fixed end "and one free end, meansfor feeding said stock downwardly, suitable burners arranged to heat aportion of the stock fed throilgh theiholdingvmeans, means forproan-upwardendwise pressure on the free end of' the stock below -.theholding ineans-,;-whe reby an. enlargement-may be pro-,

'duced at the heated portion, means for molding the enlargement'to thedesired configuration anddimensions means for tapering theestock'below-theenlargement, and means-for.-sev.ering-- the .stockabove theenlargement; H trial- A machine 'comprising a holding means I :for-.=suspending a predetermined lengthof elongated stock, means for feedingthe .stock '-.through the holding means,

- suitable burners in cooperative relation with 'saida-stock arranged toheat a portion of the sametoifusion temperature, means for rotatingthestock on its longitudinal axls,

an abutment upon which the lower end of the stock may engage,means forcausingthe abutfiltnt 'ito moveupward and produce a longitudinalendwise,. pressure on the stock whereby the heated portion of the latteris expanded and an enlargement formed, means for molding saidenlargement to a contour comprising convex bearing surfaces merging withthe stock by means of nonangular regions, means arranged to size a boreof substantially uniform cross-section I through the heated portion ofthe channel,

means for severing the article thus formed from thestock so as toinclude the enlar ement, and means for actuating the hol er andcooperative mechanisms to perform the 5 operations specified in thedesired sequence.

article, means for producing 15. A machine comprising a holder for apredetermined length of stock of vitreous material, a bore-sizing pin inthe channel around which the'elongated stock revolves concentrically,means for supporting the pin in fixed relation to the channel, means forheating the stock to its plastic temperature,

means for expanding a portion of the heated means, mechanism forapplying endwise pressure on,the end of the stock opposite the hgldingmeans' to form anenlargement, means arranged to size a bore of thereuired cross-section and substantial uniormity through the heatedportion of the a tapered tip below the enlargement, a pm arranged to rthe sizea bore of reduced cross-section through the tapered-portionofthe article commu nicating with the first-mentioned bore,

mechanism for externally. shaping the enlargement to provide sphericalbearing surfacesmergingwith the stock in non-an ar surfaces, and meansfor severing the finished article from the stock.

. 17. In combination with an apparatus of character -described forproducing shaped articles of vitreous silica having a channel extendinglengthwise therethrough a holding means for sustaining a predeten minedlength'of vitreous silica stock, instrumentalities arranged to heat thestock to its plastic temperature, a pin having a substantially squarecross-section arranged to rotate in the channel in one direction meansfor rotating the stock about the pin in the opposite direction whereby abore is sized to predetermined diameter and of uniform crosssectionthrough the article, mechanism for applying an endwise pressure on theend .of the stock opposite the holding means to form an enlargement ofthe desired configuration and accuracy of dimensions, -means for shapingthe stock'below the'enlargement to form a tip, and cooperative mechanism"for ksevering the finished article from the stoc 18. A machine of theclass describedvcom prising means for locally heating and sof-. teningelongated silica stock, means for;

forming an enlargement on said stock, means for shaping the softenedportion of the stock, a sizing pin adapted to enter the channel and tohave relative motion with respect to the stock, means for withdrawingthe sizing pin from the stock, and means for detaching the article thusformed from the stock.

19. A machine of the class described comprising means for holding alength of stock,

means for directing suitable flames against a portion'of said stock tofuse said portion,

means for subsequently forming an enlar ement of said, fused portion,means for mo ding the enlargement to a figure partially confined byconvex surfaces having the same radii and by other convex surfaceshavingdifferent radii from the first, means for shapf ing an extension of thefused stock below 'the'enlargement, means arranged to size a 'bore ofsubstantially uniform cross-section through the fused portion ing thefinished article from the stock. in cluding a shaft of predeterminedlength above the enlargement, and means whereby all of the aforesaidmeans are brought into anal out of operation in a predetermined or er.

20. A machine of the class described 06m;

prising means for locally heating and soft tening a length of vitreousstock, means for means for detach- 4 shaping the-softened portion of thestock to 5 provide an enlargement, means for sizing a bore through saidstock, and a trimming tool having a shaped surface and a cutting edgefor simultaneously shaping and trimming shape the enlargement andadjacent portions of the stock while heated to a plastic temperature,means adapted to indent the skin of the stock circumferentially whilesaid skin is plastic thus securing a weak plane for subsequent breakage,and a hammer and anvil cooperatively related to each other and to thestock whereby the latter may be readily severed at the indentation.

v 22. A machine of the class described comprising means for locallyheating and softening a length of stock, means for forming anenlargement on said stock, molding means arranged to shape theenlargement and adjacent portions of the stock, means for sizing a boreof substantially uniform cross-section through the formed article, meansfor indenting the outer surface of the stock, an anvil cooperating withthe stock at the indentation formed by the indenting means, and a hammercooperating with the anvil and adapted to hit the stock and break it 0d.

23. A machine of the class described comprising means for locallyheating and softening a length of stock, having means for .forming anenlargement on said stock,

molding means arranged to shape the enlargement and adjacent portions ofthe stock comprising rolls, means for heating the base portion of saidrolls to minimize the conduction of heat away from the stock, and meansfor finally breaking ofi the stock thus shaped.

24:. A machine of the class described comprising means for locallyheating and softening a length of stock, means for forming anenlargement on said stock, shaping rolls arranged to shape theenlargement and adjacent portions of the stock, means forv bringing saidrolls repeatedly into molding relation with said stock, means for auto;matically' heating said stock between suc cessive rolling operations,and means for cutting oil and delivering thelfinished product to asuitable receptacle.

25. In an apparatus for producing from elongated stock, shaped articleshaving a longitudinal opening therethrough, the comstock, a pin arrangedto move into and out of a longitudinal zone or said shaped portionandmeans for producing a difierence in speed of rotation between saidstock and said pin.

26. In a machine of the class described, means for locally heating andsoftening a length of stock, means for forming an enlargement on theheated portion of said stock, molding means arranged to shape portionsof the stock adjacent said enlargement comprising rotatably mountedmembers and means for heating one portion only of said members tominimize the conduction of heat away from the stock, the unheatedport-ion of said members having a concave contour which forms a seat forsaid enlargement.

lln witness whereof, we have hereunto set our hands. a

. lllltVllN 1F. HUUPER.

BERTHQLD F. NIEDERGESASS. PHILIP K. DEVERS.

bination of holding means for suspending elongated stock at one endonly, means for heat ng a portion of said stock to plasticity, rollsarranged for shaping externally to a desired contour the plastic portionof the

